Fish consumption in relation to type 2 diabetes and cardiovascular complications

Type 2 diabetes is a major public health threat globally, associated with severe medical complications such as cardiovascular diseases and damage to kidneys, eyes, and nerves, as well as with premature death. Dietary factors are of importance in both primary prevention and disease management. Fish consumption is of interest given the observed benefits on several cardiometabolic risk factors. Such benefits have largely been attributed to the content of long-chain omega-3 fatty acids, but may also be related to a wider range of nutrients. On the negative side, there is also the potential of adverse effects by contaminants present in some types of fish. This thesis includes four papers in which we aimed to: 1) summarize results from prospective studies on the associations of fish consumption and intake of long-chain omega-3 fatty acids with risk of type 2 diabetes; 2) evaluate the validity of food frequency questionnaire (FFQ)- based estimates of these exposures; 3) examine the associations of total and specific types of fish with risk of type 2 diabetes, taking environmental contaminants into account; and 4) examine the associations of total and specific types of fish with risk of myocardial infarction (MI), stroke, and mortality among people with diagnosed type 2 diabetes. Our meta-analysis showed that the accumulated observational evidence on fish consumption and long-chain omega-3 fatty acid intake in relation to type 2 diabetes risk is heterogeneous across regions, with an increased risk reported in studies conducted in the US, no association reported in European studies, and lower risk reported in Asian/Australian studies. The three latter papers are based on data from two large Swedish population-based cohorts of nearly 90,000 women and men, whose dietary habits were assessed via FFQs in 1997. We showed that the estimates of long-chain omega-3 fatty acid intake correlated with adipose tissue content of these fatty acids in a subsample of 239 women, supporting their validity. Participants were followed for the outcomes of interest through December 2012, by linkage to nationwide registers. In men, total fish consumption was not associated with type 2 diabetes in the primary analysis. Taking dietary exposure to polychlorinated biphenyls (PCBs) and methylmercury (MeHg) into account, there was however a suggestion of an inverse association. High consumption of shellfish and fried fish was associated with higher risk of type 2 diabetes. Among women and men with type 2 diabetes before baseline, fish consumption was inversely associated with MI, while there was no support for an association with stroke. The results for total and coronary heart disease (CHD)-related mortality were inconclusive with some suggestion of lower risk associated with moderate fish consumption. Overall, the results presented in this thesis do not challenge the current recommendations on regular fish consumption. General advice may however be too imprecise, and more specific recommendations on fish species and preparation methods may be warranted

Improving Software Citation and Credit

The past year has seen movement on several fronts for improving software citation, including the Center for Open Science's Transparency and Openness Promotion (TOP) Guidelines, the Software Publishing Special Interest Group that was started at January's AAS meeting in Seattle at the request of that organization's Working Group on Astronomical Software, a Sloan-sponsored meeting at GitHub in San Francisco to begin work on a cohesive research software citation-enabling platform, the work of Force11 to "transform and improve" research communication, and WSSSPE's ongoing efforts that include software publication, citation, credit, and sustainability. Brief reports on these efforts were shared at the BoF, after which participants discussed ideas for improving software citation, generating a list of recommendations to the community of software authors, journal publishers, ADS, and research authors. The discussion, recommendations, and feedback will help form recommendations for software citation to those publishers represented in the Software Publishing Special Interest Group and the broader community.Comment: Birds of a Feather session organized by the Astrophysics Source Code Library (ASCL, http://ascl.net/ ); to be published in Proceedings of ADASS XXV (Sydney, Australia; October, 2015). 4 page

Egg consumption and risk of type 2 diabetes: a prospective study and dose-response meta-analysis.

AIMS/HYPOTHESIS: In this study, we aimed to investigate the association between egg consumption and type 2 diabetes risk in the Cohort of Swedish Men and to conduct a meta-analysis to summarise available prospective evidence on this association. METHODS: We followed 39,610 men (aged 45-79 years) from 1998 up to 2012 for incident type 2 diabetes. Egg consumption was assessed at baseline using a food frequency questionnaire. HRs (95% CIs) were estimated using Cox proportional hazards regression models. We searched PubMed (up to 14 December 2015) and reference lists of retrieved articles to identify eligible studies for meta-analysis. RESULTS: During the 15 years of follow up, 4,173 men were diagnosed with type 2 diabetes. Compared with men who consumed eggs <1 time/week, the multivariable-adjusted HRs were 0.98 (95% CI 0.92, 1.05), 1.11 (95% CI 0.99, 1.24) and 1.11 (95% CI 0.95, 1.29) for egg consumption 1-2, 3-4 and ≥5 times/week, respectively (p trend = 0.06). In a random-effects dose-response meta-analysis, heterogeneity in the overall estimate was partly explained by differences across regions. The overall HRs for type 2 diabetes for each 3 times/week increment in consumption were 1.18 (95% CI 1.13, 1.24) in five US studies (I (2) = 0%) and 0.97 (95% CI 0.90, 1.05) in seven non-US studies. CONCLUSIONS/INTERPRETATION: Our findings in Swedish men do not support an association between egg consumption and risk of type 2 diabetes. In a meta-analysis, frequent egg consumption was associated with a higher risk of type 2 diabetes in US studies only. Egg consumption habits and associated overall dietary patterns may differ between populations and could potentially explain the discrepancies between reported results. Given the inconsistent results, this relationship warrants further study.This work was supported by research grants from the Swedish Research Council/Committee for Research Infrastructure for maintenance of the Cohort of Swedish Men and by a Young Scholar Award from the Karolinska Institutet’s Strategic Program in Epidemiology. NGF is supported by MRC support from MC_UU_12015/5.This is the final version of the article. It first appeared from Springer via https://doi.org/10.1007/s00125-016-3923-

Practices in source code sharing in astrophysics

While software and algorithms have become increasingly important in astronomy, the majority of authors who publish computational astronomy research do not share the source code they develop, making it difficult to replicate and reuse the work. In this paper we discuss the importance of sharing scientific source code with the entire astrophysics community, and propose that journals require authors to make their code publicly available when a paper is published. That is, we suggest that a paper that involves a computer program not be accepted for publication unless the source code becomes publicly available. The adoption of such a policy by editors, editorial boards, and reviewers will improve the ability to replicate scientific results, and will also make the computational astronomy methods more available to other researchers who wish to apply them to their data.Comment: Accepted by Astronomy and Computing. 10 page

Fish consumption and frying of fish in relation to type 2 diabetes incidence: a prospective cohort study of Swedish men.

PURPOSE: Epidemiological evidence on the association between fish consumption and risk of type 2 diabetes is heterogeneous across geographical regions. Differences related to fish consumption pattern could possibly help explain the discrepancy between the findings. We therefore aimed to investigate the association between fish consumption (total, fried, specific fish items) and type 2 diabetes incidence, taking exposure to contaminants present in fish (polychlorinated biphenyls and methyl mercury) into consideration. METHODS: The population-based Cohort of Swedish Men, including 35,583 men aged 45-79 years, was followed from 1998 to 2012. We estimated hazard ratios (HRs) with 95 % confidence intervals (CIs) using Cox proportional hazards models. RESULTS: During 15 years of follow-up, 3624 incident cases were identified. Total fish consumption (≥4 servings/week vs. <1 serving/week) was not associated with type 2 diabetes in multivariable-adjusted analysis (HR 1.00; 95 % CI 0.85-1.18); however, a statistically non-significant inverse association was observed after adjustment for dietary contaminant exposures (HR 0.79; 95 % CI 0.60-1.04). Fried fish (≥6 servings/month vs. ≤1 servings/month) and shellfish consumption (≥1 serving/week vs. never/seldom) were associated with HRs of 1.14 (95 % CI 1.03-1.31) and 1.21 (95 % CI 1.07-1.36), respectively. CONCLUSIONS: We observed no overall association between total fish consumption and type 2 diabetes. The results indicated that dietary contaminants in fish may influence the relationship. Fried fish and shellfish consumption were associated with higher type 2 diabetes incidence. These findings suggest that more specific advice on fish species sub-types (varying in contamination) and preparation methods may be warranted.This work was supported by research grants from the Swedish Research Council/Committee for Research Infrastructure for maintenance of the Cohort of Swedish Men, from the Karolinska Institutet's Award for PhD students (KID-funding) and from the Karolinska Institutet's Distinguished Professor Award. NGF acknowledges core support from the Medical Research Council Epidemiology Unit (MC_UU_12015/5).This is the final version of the article. It first appeared from Springer via https://doi.org/10.1007/s00394-015-1132-